Resumen en español

Constructed wetlands appear at the present time like a promising technology in reducing the pollution by waste waters; this study investigated the organic matter removal with synthetic waste water, in terms of chemical oxygen demand (COD), biological oxygen demand (BOD5) and in situ measurements of pH, oxygen and temperatura every 15 days, during three months, in six horizontal subsurface-flow constructed wetland systems, in pilot scale, seeded with three different macrophytes: Canna limbata, Heliconia psittacorum and Phragmites sp; the average removals of COD were of 97,31 % and 95,94 % for Canna limbata; 94,49 % and 93,50 % for Heliconia psittacorum; 97,39 % and 97,13 % for Phragmites sp. In BOD they were of 100 % and 99,36 % for Canna limbata; 99,09 % and 97,49 % for Heliconia psittacorum; 100 % and 99,45 % for Phragmites sp. We conclude that there are significant differences in DQO removal between different plants (P < 0,05); in BOD5 removal significant differences between the different plants do not exist statistically (P < 0,05). This study demonstrates the option to reduce the polution from organic matter using constructed wetlands.